Climate change is threatening the Latin American zones most favorable for growing coffee, according to a study out Monday that warns production could drop by nearly 90 percent by 2050.

The study suggests high-quality coffees are most at risk – with Arabica coffee unable to withstand even slight fluctuations in temperature, humidity and sunlight.

Robusta coffee, grown primarily in Africa to be made into instant coffee, is slightly more resistant.

“Coffee is one of the most valuable commodities on Earth, and needs a suitable climate and pollinating bees to produce well,” said study co-author Taylor Ricketts, director of the University of Vermont’s Gund Institute for Environment. “This is the first study to show how both will likely change under global warming – in ways that will hit coffee producers hard.”

During the study, published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS), researchers estimated changes to Arabica coffee distribution in Latin America and 39 species of pollinating bees.

They concluded that a temperature increase of over 3.6 degrees Fahrenheit (two degrees Celsius) by 2050 will reduce production by between 73 and 88 percent in locations best known for coffee production today.

A fall in the bee population of eight to 18 percent will also contribute to this decline.

The largest production losses are expected in Honduras, Nicaragua and Venezuela.

Researchers suggested that rising temperatures could actually increase bee population and diversity in other areas is in fact likely to increase – but only because mountainous areas currently unsuitable for coffee will become warmer. This could take place in countries such as Colombia, Costa Rica, Guatemala and Mexico, the study said.

The study also highlights the importance of tropical forests for bees and other key pollinators.

Approximately 91 percent of Latin America’s most fertile areas for coffee production are currently less than 1.2 miles (1.9 kilometers) from a rainforest.